In 2008, jet fuel prices and the AMEX airline index have had a correlation of -0.62. This implies that roughly 62% of the time that jet fuel prices fell the airline index rose. Over the last 2 months (September to October) jet fuel prices have fallen 35%, while the airline index has also fallen 6%. Based on inferences from the correlation analysis it appears that the last 2 months are part of the 38% of the time that the airline index does not trade inversely to jet fuel prices.
However, from October 10th, the airline index gained 49%, while jet fuel prices have fell 16%. A possible explanation is that the airline index was a victim of the market turmoil and is beginning to adjust to lower fuel prices.
The major airline company equity prices have held up well relative to the S&P 500 over the last six months. In fact, all except for Southwest Airlines (symbol: LUV) have positive relative strength vs. the S&P 500. Southwest Airlines aggressively hedges fuel costs and therefore the relative underperformance may be the result of its lack of sensitivity to falling fuel prices.
Relative Strength vs. the S&P 500
Symbol | 4 wk | 13 wk | 26 wk | 52 wk |
AMR | 25.38% | 49.24% | 58.86% | 10.31% |
| 41.34% | 88.75% | 46.95% | -10.93% |
DAL | 58.50% | 85.51% | 88.53% | -15.15% |
JBLU | 39.33% | 37.26% | 64.96% | -2.68% |
LCC | 77.28% | 155.64% | 69.70% | -41.17% |
LUV | -0.54% | -3.07% | 27.82% | 33.21% |
UAUA | 103.71% | 130.99% | 33.73% | -51.84% |
Source: TradeStation | | | | |
The relative strength table illustrates that Southwest Airlines has underperformed the S&P 500 during the recent fall in jet fuel prices. The 52 week relative strength figures indicate that the rising jet fuel prices over the last year could have hurt the performance of airline stocks.
The inference that one may be tempted to draw is that prices of airline stocks should rise further if jet fuel falls further. However, there are two flaws in that line of thinking. First correlation does not necessarily imply predictive ability. In other words, it could just be a coincidence that jet fuel prices and the price of the airline stocks are correlated. Second, the economic environment must be taken into consideration. A falling GDP certainly cannot bode well for the prices of airline stocks. Performing a regression analysis will add an element of certainty to the inferences.
Beginning with jet fuel prices, the regression analysis can determine if the price of the airline index is a function of jet fuel prices. Analyzing the daily closing prices of jet fuel and the airline index from January 1995 to October 2008 yielded the following results:
The inference that one may be tempted to draw is that prices of airline stocks should rise further if jet fuel falls further. However, there are two flaws in that line of thinking. First correlation does not necessarily imply predictive ability. In other words, it could just be a coincidence that jet fuel prices and the price of the airline stocks are correlated. Second, the economic environment must be taken into consideration. A falling GDP certainly cannot bode well for the prices of airline stocks. Performing a regression analysis will add an element of certainty to the inferences.
Beginning with jet fuel prices, the regression analysis can determine if the price of the airline index is a function of jet fuel prices. Analyzing the daily closing prices of jet fuel and the airline index from January 1995 to October 2008 yielded the following results:
Regression Results of AMEX Airline Index Price on Jet Fuel Price
| Coefficient | P-value |
Jet Fuel | -0.38 | 0% |
| | |
R Squared | .3931 | |
Adj. R Squared | .3929 | |
The analysis indicates that 39% (R Squared) of the movement in the AMEX airline index can be explained by movements in the price of jet fuel. Furthermore, the P-value of 0% indicates that there is virtually no chance that the price of jet fuel is unrelated to the price of the airline index.
Moving on to GDP quarterly data was used; the average daily close over the quarter was used for the quarterly price of the airline index.
Moving on to GDP quarterly data was used; the average daily close over the quarter was used for the quarterly price of the airline index.
Regression Results of AMEX Airline Index Price on Quarterly Change in GDP
| Coefficient | P-value |
Qtr. Change in GDP | 5.40 | 9.15% |
| | |
R Squared | .0528 | |
Adj. R Squared | .0349 | |
The results of the GDP analysis suggest that only 5% (R squared) of the price change in the airline index can be explained by changes in GDP. Further, there is 9% chance that GDP has no relation to the price of the airline index. These results suggest that GDP growth, or lack thereof, should not be a concern to airline investors.
Combining the two variables (change in GDP and Jet Fuel Price) produces results that further question the relevance of GDP.
Combining the two variables (change in GDP and Jet Fuel Price) produces results that further question the relevance of GDP.
Regression Results of AMEX Airline Index Price on Quarterly Change in GDP and Jet Fuel Prices
| Coefficient | P-value |
Qtr. Change in GDP | 1.36 | 60.69% |
Jet Fuel Prices | -.3792 | 0% |
| | |
R Squared | .4021 | |
Adj. R Squared | .3791 | |
Using both variables, the results suggest there is a 60% chance that the price of the airline index is unrelated to the change in GDP. As well, the price of jet fuel does have a statistically significant role to play in the price of the airline index.
The results explain why airline stocks have been rising while GDP has been falling or has been expected to fall; GDP in fact has little to do with the price of airline stocks. While jet fuel prices are not the sole determinant of airline stock prices, they play an important role.
The results explain why airline stocks have been rising while GDP has been falling or has been expected to fall; GDP in fact has little to do with the price of airline stocks. While jet fuel prices are not the sole determinant of airline stock prices, they play an important role.
Disclosure: I am long CAL and JBLU
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